THE ISOTOPE EFFECTS ON THE PHYSICAL PROPERTIES RELATED TO THE ATOMIC VIBRATION, SUCH AS IONIC CONDUCTIVITY OF SUPERIONIC CONDUCTORS, THERMAL CONDUCTIVITIES OF THERMOELECTRIC MATERIALS AND PHASE TRANSITION OF FERROELECTRIC MATERIALS WERE INVESTIGATED.THE LITHIUM IONIC CONDUCTIVITY OF (LaィイD21/2ィエD2 LiィイD21/2ィエD2)ィイD21-XィエD2SrィイD2XィエD2TiOィイD23ィエD2 (X=0, 0.05), WHICH HAS BEEN KNOWN AS THE CONDUCTOR HAVING THE MOST HIGHEST Li IONIC CONDUCTIVITY, WAS MEASURED USING THE ィイD16ィエD1Li-ENRICHED AND ィイD17ィエD1Li-ENRICHED SAMPLES. THE Li IONIC CONDUCTIVITY OF ィイD16ィエD1Li-ENRICHED SAMPLE WAS ABOUT 1.5 TIMES HIGHER THAN THAT OF ィイD17ィエD1Li-ENRICHED ONE, WHOSE HIGHER VALUE CAN NOT BE EXPLAINED BY THE CLASSICAL DIFFUSION MODEL. THE GLASS TRANSITION TEMPERATURE AND IONIC CONDUCTIVITY OF 0.33LiィイD22ィエD2O-0.67BィイD22ィエD2OィイD23ィエD2 GLASS WERE MEASURED BY VARYING ィイD16ィエD1Li / ィイD17ィエD1Li AND ィイD110ィエD1B / ィイD111ィエD1B ISOTOPE RATIOS IN THE SAMPLES. THE CHANGE IN THE GLASS TRANSITION WAS NOT CLEARLY OBSERVED. HOWEVER THE Li IONIC CONDUCTIVITY OF ィイD16ィエD1 Li-ENRICHED SAMPLE WAS ABOUT 2.2 TIMES HIGHER THAN THAT OF ィイD17ィエD1Li-ENRICHED ONE AT 500K, AND THAT OF ィイD110ィエD1B-ENRICHED SAMPLE WAS ABOUT 1.4 TIMES HIGHER THAN THAT OF ィイD111ィエD1B-ENRICHED SAMPLE AT 500K, SUGGESTING THE PRESENCE OF STRONG CORRELATION BETWEEN Li-IONS AND ALSO THE RELAXATION VIBRATION OF THE B-O NETWORK STRUCTURE.THE ISOTOPE EFFECT ON FERROELECTRIC PHASE TRANSITION OF PbTiOィイD23ィエD2 WAS MEASURED. THE TRANSITION TEMPERATURE OF ィイD146ィエD1Ti-ENRICHED SAMPLE WAS ABOUT 8.8K HIGHER THAN THAT OF ィイD149ィエD1Ti-ENRICHED SAMPLE.